Trametinib (Mekinist™)

OncoLink The Abramson Cancer Center of the University of Pennsylvania

Pronounced: tra-ME-ti-nib Classification: Kinase Inhibitor

About Trametinib

BRAF is a protein kinase that plays a role in regulating genes that are responsible for cell replication and survival. It is estimated that 50% of melanomas contain an abnormal form of BRAF (also called/known as a BRAF mutation). This mutated form of BRAF appears to promote overgrowth of these cancer cells. Trametinib works by blocking the actions of the abnormal BRAF, inhibiting cell replication and potentially causing cell death.

How to Take Trametinib

Trametinib is given in a tablet form and is typically taken once a day. Trametinib tablets should be taken on an empty stomach (1 hour before or 2 hours after meals) and should not be crushed, broken or chewed. If you miss a dose, take it as soon as you remember. If it is within 12 hours of your next dose, skip the missed dose and take the next dose at your regular time. Do not take two doses at once to make up for a missed dose.

Store the medication in the refrigerator, in the original bottle with the desiccant packet. Do not use a pill box for this medication.

BRAF Testing

Because this medication only works in cancer that has one of 2 specific BRAF mutations called V600E and V600K, the tumor will be tested for this abnormality prior to starting the medication to determine if this therapy is appropriate for you. In order to test for mutated BRAF, a sample of the tumor is sent to a special laboratory that performs this test.

Possible Side Effects of Trametinib

There are a number of things you can do to manage the side effects of Trametinib. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:

Rash & Hand Foot Syndrome

Some patients develop a skin rash or redness, or a rash that looks like acne. This rash can become severe and result in skin infection and hospitalization. Find tips for dealing with dry skin and rash on OncoLink.

Hand-foot syndrome is a skin reaction that appears on the palms of the hands and/or the soles of the feet as a result of certain chemotherapy agents. It can start as a feeling of tingling or numbness in the palms and/or soles and progress to swelling, redness, peeling skin, and tenderness or pain.

Notify your healthcare team right away if you notice any skin reactions so they can make recommendations or dose changes to prevent them from getting worse.

High Blood Pressure

High blood pressure (hypertension) was seen in clinical trials and typically occurred within the first few months of therapy. Patients should have their blood pressure checked regularly during therapy. If you develop headaches, light headedness or dizziness, notify your healthcare team.

Diarrhea

Your oncology team can recommend medications to relieve diarrhea. Try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads, cereals and seeds. Soluble fiber is found in some foods that absorbs fluid and can help relieve diarrhea. Foods high in soluble fiber include: applesauce, bananas (ripe), canned fruit, orange and grapefruit sections, boiled potatoes, white rice and products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses on non-alcoholic, un-caffeinated fluid a day to prevent dehydration. Read Low Fiber Diet for Diarrhea for more tips.

If you experience severe diarrhea, notify your healthcare team as this can lead to life-threatening dehydration.

Lung Problems

In a few cases, patients developed a rare lung problem called Interstitial Lung Disease (ILD) while receiving trametinib. Notify your healthcare team right away if you develop shortness of breath, new or worsening cough or have any difficulty breathing.

Heart Issues

Trametinib can cause a heart problem called cardiomyopathy, which affects the heart muscle, making it weaker and less able to pump blood (called heart failure) or have an abnormal rhythm (called arrhythmia). Your healthcare provider will monitor for this problem with periodic heart scans (called MUGA scans). If you develop shortness of breath, swelling in the legs, feet or ankles, irregular heartbeats, light-headedness or chest pain, notify your healthcare provider right away.

Eye Issues

In clinical trials, several patients developed eye conditions that affected their vision. Symptoms of these conditions include blurry vision, loss or change in vision, seeing colored dots or halos (blurry outline around objects). If you develop any of these symptoms, notify your healthcare provider right away.

Reproductive Concerns

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control is necessary during treatment and for at least 4 months after, even if your menstrual cycle stops or you believe your sperm is affected.

You may want to consider fertility preservation if you may wish to have a child in the future. Discuss these options with your oncology team. See OncoLink's section on fertility for helpful tips for dealing with these side effects.